Studies of synthesis and permeabilities of special polymer membranes. LI. Active transport of halogen ions through chitosan membranes

Uragami, Tadashi; Yoshida, Fumitake; Sugihara, Mizuho

doi:10.1002/app.1983.070280410

Cited by 58 publications

(15 citation statements)

References 14 publications

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“…PVA material was dissolved in a mixture consisting of distilled water and ethanol in a ratio of 4 : 1. Gelatin was dissolved in distilled water and added to a PVA solution in different percentages of gelatin (2,5,7,10, and 15 wt %). The films of pure and doped PVA were cast on glass plates of distilled water and ethanol solutions and slowly dried in an air oven at 25°C for 72 h to minimize gelation effects.…”

Section: Methodsmentioning

confidence: 99%

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Optical studies of pure and gelatin-doped poly(vinyl alcohol) films irradiated with fast neutrons

El‐Kader

Gaafar

Rizk

et al. 1999

J. Appl. Polym. Sci.

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ABSTRACT:The ultraviolet (UV) and infrared (IR) spectra of pure poly(vinyl alcohol) (PVA) and gelatin-doped PVA films with concentrations (2, 5, 7, 10, and 15 wt %) were studied before and after irradiation with neutron fluences in the range of 10 5 -10 8 n/cm 2 . The obtained data revealed that the addition of gelatin and neutron irradiation causes structural variation in the PVA network. The analysis of the UV spectra showed that the increase of dopant concentration above 5 wt % gelatin makes the sample less resistant to a degradation effect caused by neutron irradiation. It was also found that the intensity of the band at 210 nm increases by increasing dopant concentration. Careful examination of the infrared spectra indicated that the induced percent crystallinity of the sample containing 5 wt % gelatin has more stability than the other doped samples. Neutron irradiation also results in the appearance of new absorption bands and irregular change in the absorbance of some IR bands.

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Section: Methodsmentioning

confidence: 99%

“…[1][2][3][4] Exposure of polymers to fast neutron irradiation causes changes in structure and, hence, in chemical and physical properties. [5][6][7][8][9] Poly(vinyl alcohol) (PVA) is a nontoxic watersoluble synthetic polymer that is widely used in biochemical and biomedical applications.…”

Section: Introductionmentioning

confidence: 99%

Optical studies of pure and gelatin-doped poly(vinyl alcohol) films irradiated with fast neutrons

El‐Kader

Gaafar

Rizk

et al. 1999

J. Appl. Polym. Sci.

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“…Thus, there is need to develop better hemodialysis membranes to provide greater selectivity and higher dialysis rates for medium-and largesize molecules such as uric acid and the like. A considerable amount of work has been reported in literature either on modification of existing polymeric membranes or on synthesis of new polymeric membranes to meet the requirement of dialysis applications [163][164][165].…”

Section: Artificial Kidney Membranementioning

confidence: 99%

Chitosan: The Most Valuable Derivative of Chitin

Nayak¹

2011

Biopolymers

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“…The hydroxide ions deprotonate the -NH 3 + group of the dissolved chitosan to form a chitosan precipitate. This technique has been applied to produce porous hydrogel (Dang et al 2011), beads (Rorrer et al 1993), fibers (Suzuki 1993) (1992, patent appl date), membranes (Uragami et al 1983), and sponges (Denkbaş and Odabaşi 2000). The acidic chitosan solution can be converted to semi-solid phase through a gelation process.…”

Section: Properties Of Chitosanmentioning

confidence: 99%

Environmental Applications of Chitosan and Its Derivatives

Yong

Shrivastava

Srivastava

et al. 2014

Reviews of Environmental Contamination and Toxicology

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Chitosan originates from the seafood processing industry and is one of the most abundant of bio-waste materials. Chitosan is a by-product of the alkaline deacetylation process of chitin. Chemically, chitosan is a polysaccharide that is soluble in acidic solution and precipitates at higher pHs. It has great potential for certain environmental applications, such as remediation of organic and inorganic contaminants, including toxic metals and dyes in soil, sediment and water, and development of contaminant sensors. Traditionally, seafood waste has been the primary source of chitin. More recently, alternative sources have emerged such as fungal mycelium, mushroom and krill wastes, and these new sources of chitin and chitosan may overcome seasonal supply limitations that have existed. The production of chitosan from the above-mentioned waste streams not only reduces waste volume, but alleviates pressure on landfills to which the waste would otherwise go. Chitosan production involves four major steps, viz., deproteination, demineralization, bleaching and deacetylation. These four processes require excessive usage of strong alkali at different stages, and drives chitosan's production cost up, potentially making the application of high-grade chitosan for commercial remediation untenable. Alternate chitosan processing techniques, such as microbial or enzymatic processes, may become more cost-effective due to lower energy consumption and waste generation. Chitosan has proved to be versatile for so many environmental applications, because it possesses certain key functional groups, including - OH and -NH2 . However, the efficacy of chitosan is diminished at low pH because of its increased solubility and instability. These deficiencies can be overcome by modifying chitosan's structure via crosslinking. Such modification not only enhances the structural stability of chitosan under low pH conditions, but also improves its physicochemical characteristics, such as porosity, hydraulic conductivity, permeability, surface area and sorption capacity. Crosslinked chitosan is an excellent sorbent for trace metals especially because of the high flexibility of its structural stability. Sorption of trace metals by chitosan is selective and independent of the size and hardness of metal ions, or the physical form of chitosan (e.g., film, powder and solution). Both -OH and -NH2 groups in chitosan provide vital binding sites for complexing metal cations. At low pH, -NH3 + groups attract and coagulate negatively charged contaminants such as metal oxyanions, humic acids and dye molecules. Grafting certain functional molecules into the chitin structure improves sorption capacity and selectivity for remediating specific metal ions. For example, introducing sulfur and nitrogen donor ligands to chitosan alters the sorption preference for metals. Low molecular weight chitosan derivatives have been used to remediate metal contaminated soil and sediments. They have also been applied in permeable reactive barriers to remediate metals in soil and groun...

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Studies of synthesis and permeabilities of special polymer membranes. LI. Active transport of halogen ions through chitosan membranes

Cited by 58 publications

References 14 publications

Optical studies of pure and gelatin-doped poly(vinyl alcohol) films irradiated with fast neutrons

Optical studies of pure and gelatin-doped poly(vinyl alcohol) films irradiated with fast neutrons

Chitosan: The Most Valuable Derivative of Chitin

Environmental Applications of Chitosan and Its Derivatives

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